This invention relates generally to coaxial cables and more particularly concerns a coaxial cable with a low reflection coefficient and low insertion loss.
In the transmission of high-frequency signals, particularly in the gigahertz range, the structure of transmission cables is extremely critical. Moreover, such cables are often subject to flexure and other physical shocks which make the physical arrangement of the components even more critical.
Thus, it is desired to provide a transmission line having low insertion loss and a low reflection coefficient (VSWR), in a cable that will provide a stable VSWR and insertion loss under flexure and other shock conditions.
One of the problems in constructing such a coaxial cable is meeting required critical electrical tolerances. For example, if it is desired to produce a coaxial cable with a characteristic impedance of fifty ohms plus or minus one ohm, it is often difficult to vary the conductors or dielectric to provide an impedance within that range. Accordingly with the present invention, while producing the cable, routine tests can be run and a detent can be varied slightly to correct the impedance to within the desired range. Thus, a detent can easily be pressed into corrugated outer conductor elements before assembly or an assembled cable without its protective wire mesh braid and plastic outer jacket can be further compressed to provide the desired characteristic impedance.